MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 760

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

22.5.4 CLAMP
22.5.5 HI-Z
22.6 Restrictions
22.7 Low-Power Stop Mode
MPC555
USER’S MANUAL
When the bypass register is selected by the current instruction, the shift register stage
is set to a logic zero on the rising edge of TCK in the capture-DR controller state.
Therefore, the first bit to be shifted out after selecting the bypass register will always
be a logic zero.
The CLAMP instruction selects the single-bit bypass register as shown in
4, and the state of all signals driven from system output pins is completely defined by
the data previously shifted into the boundary scan register (e.g., using the SAMPLE/
PRELOAD instruction).
The HI-Z instruction is provided as a manufacturer’s optional public instruction to pre-
vent having to backdrive the output pins during circuit-board testing. When HI-Z is in-
voked, all output drivers, including the two-state drivers, are turned off (i.e., high
impedance). The instruction selects the bypass register.
The MPC555 / MPC556 provides flexible control of external signals using the bound-
ary scan register and EXTEST or CLAMP instructions. As a result, the circuit board
test environment must be designed to avoid signal contention which may result in de-
vice destruction.
The MPC555 / MPC556 features a low-power stop mode. The interaction of the scan
chain interface with low-power stop mode is as follows:
1. The TAP controller must be in the test-logic-reset state to either enter or remain
/
MPC556
in the low-power stop mode. Leaving the TAP controller in the test-logic-reset
state negates the ability to achieve low-power, but does not otherwise affect de-
vice functionality.
FROM TDI
SHIFT DR
IEEE 1149.1-COMPLIANT INTERFACE (JTAG)
0
Figure 22-4 Bypass Register
Rev. 15 October 2000
G1
1
1
MUX
CLOCK DR
D
C
TO TDO
Figure 22-
MOTOROLA
22-6